It is important for all of us to consider taking preventive measures against neurodegenerative diseases. Some possibilities are listed below and you are encouraged to find others.

Olfactory therapy

There is a pressing need to identify therapeutic strategies that will help individuals with Mild Cognitive Impairment (MCI) and Alzheimer disease (AD). Loss of smell or problems with sense of smell is described as a sensitive measure of the early disease process in many neurological disorders including MCI and AD. It has also been shown that olfactory function correlates with cognition levels, and volume of olfactory brain regions. Importantly, in individuals that have lost their sense of smell, or its reduced, olfactory therapy may improve olfactory function. Significantly, this therapy may also result in enhanced neurogenesis and improved odor memory, increased olfactory bulb volume and restoration of neuronal circuitry in olfactory brain regions. Olfactory therapy comprises 4 smells (rose, citronella, eucalyptus and cloves), which represent the odor prism of the main odor categories. Olfactory therapy involves smelling each odor for ~20 seconds twice/daily with 30 seconds delay between odors. For the studies that have been done, individuals are asked to do this for a period of 3-4 months.

One issue however is that olfactory therapy is not targeted for seniors (who lose their sense of smell as they age) or for individuals with a neurodegenerative disease. There has been some olfactory therapy studies conducted in individuals with Parkinson disease (Haehner et al., 2013, PLoS One; Knudsen et al 2015, Acta Neurol Scand). Olfactory function was improved and showed lasting clinical effects. It is also possible that cognitive function and odor memory may be improved. However, additional studies are required in order to ascertain this. We are currently doing such a study in individuals with Mild Cognitive Impairment.

It is becoming increasingly evident that physicians need practical clinical tools that integrate knowledge across multiple domains of function in order to make evidence based personal decisions for their patients. In order for clinicians to triage their senior patients, development of a step-wise protocol to identify pre-clinical AD cases is essential in order to put them on a track of preventive treatments (exercise, healthy eating, social interactions, brain games) that have been shown to help delay the onset of AD. It is important that olfactory testing becomes routine for seniors, and that they are offered olfactory therapy if the testing shows they have reduced olfactory function.

Thérapie olfactive

Il existe un besoin urgent d'identifier des stratégies thérapeutiques qui aideront les personnes atteintes de troubles cognitifs légers (MCI) et de la maladie d'Alzheimer (MA). La perte de l'odorat ou les problèmes d'odorat sont décrits comme une mesure sensible du processus précoce de la maladie dans de nombreux troubles neurologiques, y compris le MCI et la MA. Il a également été démontré que la fonction olfactive est en corrélation avec les niveaux de cognition et le volume des régions olfactives du cerveau. Surtout, chez les personnes qui ont perdu leur odorat, ou son odorat réduit, la thérapie olfactive peut améliorer la fonction olfactive. De manière significative, cette thérapie peut également entraîner une neurogenèse améliorée et une meilleure mémoire des odeurs, une augmentation du volume du bulbe olfactif et une restauration des circuits neuronaux dans les régions olfactives du cerveau. La thérapie olfactive comprend 4 odeurs (rose, citronnelle, eucalyptus et clou de girofle), qui représentent le prisme olfactif des principales catégories d'odeurs. La thérapie olfactive consiste à sentir chaque odeur pendant environ 20 secondes deux fois par jour avec un délai de 30 secondes entre les odeurs. Pour les études qui ont été faites, les individus sont invités à le faire pendant une période de 3 à 4 mois.

Un problème cependant est que la thérapie olfactive n'est pas destinée aux personnes âgées (qui perdent leur odorat en vieillissant) ou aux personnes atteintes d'une maladie neurodégénérative. Deux études de thérapie olfactive ont été menées chez des personnes atteintes de la maladie de Parkinson (Haehner et al., 2013, PLoS One ; Knudsen et al 2015, Acta Neurol Scand). La fonction olfactive a été améliorée et a montré des effets cliniques durables. Il est également possible que la fonction cognitive et la mémoire des odeurs soient améliorées. Cependant, des études complémentaires sont nécessaires pour le vérifier. Nous menons actuellement une telle étude chez les personnes atteintes de déficience cognitive légère.

Il devient de plus en plus évident que les médecins ont besoin d'outils cliniques pratiques qui intègrent les connaissances dans plusieurs domaines fonctionnels afin de prendre des décisions personnelles fondées sur des preuves pour leurs patients. Afin que les cliniciens puissent trier leurs patients âgés, le développement d'un protocole par étapes pour identifier les cas précliniques de MA est essentiel afin de les mettre sur une piste de traitements préventifs (exercice, alimentation saine, interactions sociales, jeux cérébraux) qui ont été montrés pour aider à retarder l'apparition de la MA. Il est important que les tests olfactifs deviennent une routine pour les personnes âgées et qu'elles se voient proposer une thérapie olfactive si les tests montrent qu'elles ont une fonction olfactive réduite.

Green Tea

The first scientific publication on the health benefits of green tea occurred in 1211 AD when Japanese monk Eisai wrote a book called Kissa-yojoki, which means “How to keep healthy drinking tea.” Since then daily green tea consumption has been heralded as a simple way to keep healthy and now researchers suggest it may even help prevent the onset of neurodegenerative diseases such as Alzheimer and Huntington disease.

Green tea leaves come from the Camellia sinensis plant and are rich in catechins called (—)-epigallocatechin-3-gallate (EGCG), which are biological antioxidants. Antioxidants are able to directly counter act the harmful effects of reactive oxygen species (ROS) such as superoxide and hydroxyl free radicals. ROS are known to cause a plethora of detrimental effects to cells which include attacking cell membranes, damaging DNA, and finally, leading to apoptosis (cell suicide). Alzheimer’s disease and Huntington disease are both characterized by excessive neuronal death which leads to atrophy of specific brain areas. A recent study carried out by Menard et al. (2013) has revealed that EGCG may also have a neuroprotective modulatory effect on intracellular signaling pathways specifically linked to cell death (Apoptosis). EGCG is able to promote neuronal interconnections and increase protein kinase C gamma activity which is an enzyme responsible for maintaining the integrity of the cell’s cytoskeleton and neural plasticity (Menard, et al. 2013). Thus, by daily consuming green tea you are providing your body with the antioxidants it needs to scavenge ROS and promote cell survival (anti-apoptotic) intracellular pathways.

Physical and mental exercise

Daily physical activity has been linked to living a longer healthier life by providing your body with more energy, lowering cholesterol, and a trimmer physique. Resistance training is any physical activity where the body works against weights or bodyweight and has been proven to beneficial for the body and the mind.

A study carried out by researchers in Vancouver divided two groups of women aged 65 to 75 into three groups. One group of women performed twice-weekly resistance training and another group performed resistance training once a week. The third group of women served as a control and performed twice a week classes that involved balance and muscle tone exercise.

The results of the study showed that after one year, women in both resistance training groups performed better at cognitive exams and were also physical stronger than the control group (Liu-Ambrose et al. 2010). Physical exercise helps maintain good blood flow to the brain, which can reduce certain risk factors for neurodegenerative diseases. Additionally, the mind should be treated as a muscle and be “worked out” as well in order to maintain mental acuity. A good example of mental activity is Sudoku, crossword puzzles, or daily engaging brain game-activities such as Lumosity.

The Mediterranean diet

Numerous studies have shown very positive benefits in people who consume a mediterranean diet. Different countries and regions have variations for this diet. However in general it is high in vegetables, fruits, legumes, nuts, beans, cereals, grains, fish, and unsaturated fats like olive oil. It usually has a low intake of meat and dairy foods.

The ketogenic diet

Huntington disease patients typically show decreased metabolism of glucose in astrocytes of the striatum. This suggests that HD pathology renders the metabolism of glucose inefficient which elects replacing glucose for a more efficient source of energy.

The ketogenic diet has been used for the symptomatic treatment of epilepsy for over 80 years. New research suggests that the ketogenic diet may also have therapeutic potential to treat neurodegenative diseases such as Alzheimer and Huntington disease. A study done by Ruskin et al. (2011) shifted the metabolism of HD mice from breaking down glucose to ketone bodies for energy by adhering to a high fat/low carbohydrate (ketogenic) diet and observed decreased weight loss. Research also suggests that ketone bodies, especially beta-hydroxybutyrate, confers neuroprotection against cellular damage (Gasior et al. 2008).

Remember that before making any drastic changes to your diet such as adhering to a ketogenic diet, you should consult your physician first.

Aromatherapy

In addition to olfactory therapy to improve olfactory function and possible help cognitive function, you may also wish to consider aromatherapy. Aromatherapy is a non-invasive alternative medicine therapy for treating illness by focusing on the effects of essential oils such as lavender, peppermint and rosemary on the body. The olfactory system interacts closely with the limbic system, which explains the phenomenon of scent memory where a particular smell may bring upon pleasant or unpleasant memories i.e the scent of apple pie reminding you of your grandmother’s delicious apple pie. Furthermore, aromatherapy is often used in conjunction with massages in which the essential oil is spread throughout the body during the massage, resulting in a soothing experience for the patient.

Alzheimer disease is a neurodegenerative disease that causes a plethora of detrimental effects on the patient’s cognitive abilities as well as their emotional state of well being. One of the early symptoms of Alzheimer’s disease (AD) is the loss of smell, which would render it difficult to treat AD patients with aromatherapy. Fortunately, Snow et al. 2010 found that application of aromas such as lavender as skin oils during the massage to be effective. The pharmacological treatments of neurodegenerative diseases may carry adverse effects or may only treat the biological aspect of the illness. The use of complimentary alternative medicine therapies such aromatherapy aims to alleviate the emotional burden of the disease on the patient. The aromatherapist as opposed to the general practitioner will go to extra lengths to relax the patient through acquired interpersonal skill training and the application of soothing aromas. However, due to a lack of scientific data to validate aromatherapy as a treatment option, many medical professionals do not support aromatherapy and regard it as complimentary modality or pseudoscience.

Nonetheless, some patients may hold strong beliefs in the efficacy of aromatherapy, which shouldn’t be ignored by the physician. As long as the aromatherapy is conducted by a certified practitioner by the Canadian Federation of Aromatherapists and doesn’t hinder the conventional therapy there shouldn’t be an issue to including it as complimentary treatment option. It’s important to note that aromatherapy itself is not being presented as being able to cure serious illness but rather being a safe and beneficial complimentary therapeutic approach in treating AD patients. After all, an aromatherapy massage remains a soothing experience for the patient, which some research suggests may even hold a mild transient anxiolytic effect (Cooke et al., 2000). Furthermore, a team of scientists specializing in psychogeriatrics performed a study of the effects of aromatherapy on Alzheimer’s disease patients and found that aromatherapy provided an efficacious non-pharmacological therapy (Jimbo et al., 2009). All patients showed significant improvements in personal orientation related to cognitive function after undergoing a period of 28 days of aromatherapy. Thus, with the recent rise of interest in non-pharmacological therapies for dementia, current research suggests that aromatherapy may provide a safe and efficacious non-pharmacological treatment to be used in conjunction with primary health care conventional therapy (Jimbo et al., 2009).

Articles for further information on non-pharmacological prevention strategies for neurodegenerative disorders:

Biol Psychiatry. 2012 May 1;71(9):783-91. Multiple biological pathways link cognitive lifestyle to protection from dementia. Valenzuela MJ¹, Matthews FE, Brayne C, Ince P, Halliday G, Kril JJ, Dalton MA, Richardson K, Forster G, Sachdev PS; Medical Research Council Cognitive Function and Ageing Study.

Cognitive lifestyle and long-term risk of dementia and survival after diagnosis in a multicenter population-based cohort. Valenzuela M, Brayne C, Sachdev P, Wilcock G, Matthews F; Medical Research Council Cognitive Function and Ageing Study. Am J Epidemiol. 2011 May 1;173(9):1004-12. PMID:21378129

Neuroimage. 2010 Oct 1;52(4):1667-76. Effects of memory training on cortical thickness in the elderly. Engvig A¹, Fjell AM, Westlye LT, Moberget T, Sundseth Ø, Larsen VA, Walhovd KB.

Aerobic exercise training increases brain volume in aging humans. Colcombe SJ, Erickson KI, Scalf PE, Kim JS, Prakash R, McAuley E, Elavsky S, Marquez DX, Hu L, Kramer AF. J Gerontol A Biol Sci Med Sci. 2006 Nov;61(11):1166-70. PMID:17167157

Familiarity or conceptual priming? Good question! Comment on Stenberg, Hellman, Johansson, and Rosén (2009). Lucas HD, Voss JL, Paller KA. J Cogn Neurosci. 2010 Apr;22(4):615-7. PMID: 19422289

Plasticity of brain networks in a randomized intervention trial of exercise training in older adults. Voss MW, Prakash RS, Erickson KI, Basak C, Chaddock L, Kim JS, Alves H, Heo S, Szabo AN, White SM, Wójcicki TR, Mailey EL, Gothe N, Olson EA, McAuley E, Kramer AF. Front Aging Neurosci. 2010 Aug 26;2. PMID: 20890449

PLoS One. 2013 Apr 9;8(4) Print 2013. A randomized controlled trial of multicomponent exercise in older adults with mild cognitive impairment. Suzuki T¹, Shimada H, Makizako H, Doi T, Yoshida D, Ito K, Shimokata H, Washimi Y, Endo H, Kato T.

Curr Transl Geriatr Exp Gerontol Rep. 2012 Apr 19;1(2):104-110. Biomarkers of Cognitive Training Effects in Aging. Belleville S¹, Bherer L.

Cognitive stimulation to improve cognitive functioning in people with dementia. Woods B, Aguirre E, Spector AE, Orrell M. Cochrane Database Syst Rev. 2012 Review. PMID: 22336813

BMJ. 2006 Dec 9;333(7580):1196. Community based occupational therapy for patients with dementia and their care givers: randomised controlled trial. Graff MJ¹, Vernooij-Dassen MJ, Thijssen M, Dekker J, Hoefnagels WH, Rikkert MG

References for articles cited

Alzheimer Society Toronto, (2014). Alzheimer Society of Toronto - Statistics. [online] Alzheimertoronto.org. Available at: http://www.alzheimertoronto.org/ad_Statistics.htm [Accessed 24 Jun. 2014].

Cooke, B., Ernst, E. (2000). Aromatherapy : a systematic review. Br J Gen Pract. 50(455): 493-496

Jimbo, D., Kimura, Y., Taniguchi, M., Inoue, M., Urakami, K. (2009). Effect of aromatherapy on patients with Alzheimer’s disease. Psychogeriatrics. 9(4) :173-9

Gasior, M., Rogawski, M.A., Hartman, A.L. (2008). Neuroprotective and disease-modifying effects of the ketogenic diet. Behav Pharmacol. 17(5-6): 431-439

Kaplan, A., Stockwell, B.R. (2012) Therapeutic approaches to preventing cell death in Huntington disease. Progress in Neurobiology. 99: 262-280

Liu-Ambrose,T., Nagamatsu L.S. Graf, G.,Beattie, B.L., Ashe, M.C., Handy, T.C.(2010) Resistance Training and Executive Functions: A 12-Month Randomized Controlled Trial. Archives of Internal Medicine, 170(2): 170-178.

Marder K, Gu Y, Eberly S, et al.(2013) Relationship of Mediterranean Diet and Caloric Intake to Phenoconversion in Huntington Disease. JAMA Neurol. 2013;70(11):

Menard, C., Bastianetto, S., Quirion, R., (2013). Neuroprotective effects of resveratrol and epigallocatechin gallate polyphenols are mediated by the activation of protein kinase C gamma. Front cell neurosci. 7:281

Ruskin, D.N., Ross, J.L., Kawamura, Jr., M., Ruiz, T.L., Geiger, J.D., Masino, S.A. (2011) A ketogenic diet delays weight loss and does not impair working memory or motor function in the R6/2 1J mouse model of Huntington disease. Physiology & Behavior. 103:501-507

Sutherland, B.A., Rahman, R., Appleton, I. (2005). Mechanisms of action of green tea catechins, with a focus on ischemia-induced neurodegeneration. Journal of Nutritional biochemistry. 17:291-306

Review articles:

Excercise

· Liu-Ambrose,T., Nagamatsu L.S. Graf, G.,Beattie, B.L., Ashe, M.C., Handy, T.C.(2010) Resistance Training and Executive Functions: A 12-Month Randomized Controlled Trial. Archives of Internal Medicine, 170(2): 170-178.

Green tea

· Mandel, S.A., Avramovich-Tirosh, Y., Reznichenko, L., Zheng, Hailin., Weinreb, O., Amit, T., Youdim, M. (2005). Multifunctional activities of green tea catechins in neuroprotection.

Ketones

· Henderson, S.T. (2008) Ketone bodies as a therapeutic for Alzheimer’s disease. Neurotherapeutics. 5(3) : 460-480